You are failing to take into the account that most Christians that subscribe to the concept of "The FALL', and the DOctrine of Original sin view God as 'Omnicient and onimpotent"
Claiming those characteristics from god leaves a logical conumdrum that is ignored by those people who claim that.
God COULD have created man with the capcity of falling, but did not. Remember, with the supposed characteristics of 'all knowing' and 'all powerful', he supposedly knows the shape of the pot before the clay is even thrown. Surely, he would know how to make the pot so it didn't shatter.